Abstract
The author questions the suggestion of Waterhouse, Hogben et al. that 3% of all conceptions in the general population of Britain die before birth owing to ABO iso-immunization. The deficiency of group A children in AO families (father group A, mother group O) in the W. of Scotland was not apparent in the consecutive series of 400 infants and children autopsied in a Glasgow hospital rather, a significant deficiency of group O children, particularly among infants evidencing signs of broncho-pneumonia, seemed to indicate an association of A and B antigens with infant deaths from broncho-pneumonia (or conditions complicated by broncho-pneumonia) to which the mechanism of ABO iso-immunization in the general population probably contributed.